Parking assist apparatus

ABSTRACT

Provided is a steering assist apparatus configured to perform a steering assist control for changing a steering angle of a vehicle in such a manner that the vehicle moves along a target path; determine whether a newly-detected object is a stationary object or a moving object; cancel the steering assist control and inform a driver that the steering assist control is cancelled when the newly-detected object is the stationary object and a cancel condition is satisfied; pause the steering assist control and inform the driver that the steering assist control is paused when the newly-detected object is the moving object and a pause condition is satisfied; and resume the steering assist control when a resume condition is satisfied.

CLAIM OF PRIORITY

The present application is a continuation of U.S. application Ser. No.16/275,447 filed Feb. 14, 2019 (allowed), which claims priority fromJapanese patent application JP 2018-25090 filed on Feb. 15, 2018. Theentire disclosures of the prior applications are considered part of thedisclosure of the accompanying continuation application, and are herebyincorporated by reference.

BACKGROUND 1. Technical Field

The present disclosure relates to a steering assist apparatus configuredto perform a steering assist control for assisting/supporting a steeringoperation of a driver when a vehicle is parked (or exits from a parkingspace).

2. Description of the Related Art

Hitherto, there is proposed a steering assist apparatus configured todetect a peripheral state of a vehicle by using vehicle peripheralsensors when the vehicle is parked at a predetermined position (targetposition), and assist a steering operation of a driver in such a mannerthat the vehicle moves/travels along a target path set based on thedetected peripheral state.

JP 2004-203359 A (paragraphs 0046 to 0049, 0059, 0060, and the like)discloses some embodiments of the above-mentioned steering assistapparatus. One of the embodiments (third embodiment in JP 2004-203359 A,hereinafter referred to as a “first related-art apparatus”) monitorswhether or not a new obstacle (e.g., pedestrian) is detected in aperiphery of the vehicle after a steering assist control for moving thevehicle along the target path is started. In a case where a new objectis detected, when a distance between the obstacle and the vehiclebecomes equal to or less than a predetermined distance threshold, thefirst related-art apparatus causes a speaker or a display device togenerate an alert/warning that the vehicle is stopped, and then, stopsthe vehicle.

After the vehicle is stopped, if the obstacle moves to a position awayfrom the vehicle within a certain time period, the first related-artapparatus resumes the steering assist control according to the targetpath which was used at the time point at which the vehicle is stopped.Meanwhile, if the obstacle does not move to a position away from thevehicle within the certain time period, the first related-art apparatusrecalculates the target path.

Further, one of the other embodiments (second embodiment in JP2004-203359 A, hereinafter referred to as a “second related-artapparatus”) determines whether or not the vehicle gets close to thenewly-detected obstacle when the vehicle moves along the target path.When it is determined that the vehicle gets close to the obstacle, thesecond related-art apparatus immediately cancels the steering assistcontrol according to that target path.

The obstacle newly detected after the setting/determination of thetarget path is typically a moving object such as a pedestrian and abicycle. On the other hand, at the time point of thesetting/determination of the target path, there is a possibility thatthe vehicle peripheral sensors cannot detect all stationary objects inthe periphery of the vehicle. Here, the “stationary object” means anobject which does not move at all or an object which does not move for along time. When a new obstacle is detected after the setting of thetarget path (in particular, after the movement of the vehicle along thetarget path is started), the newly-detected obstacle may be thestationary object.

However, even if the newly-detected obstacle is the stationary object,the first related-art apparatus does not recalculate the target pathuntil the certain time period elapses. Further, there is also a highpossibility that there is no path that allows the vehicle to move to thetarget position without coming into contact with the obstacle. In thiscase, it takes a long time for the driver to recognize/notice that “thevehicle cannot be parked unless the vehicle is moved from a currentposition of the vehicle to another position”. Therefore, there arises aproblem that a time required for parking the vehicle becomes long.

SUMMARY

One or more embodiments described below have been devised in view of theabove-mentioned problem. Specifically, the one or more embodimentsprovide a steering assist apparatus capable of canceling or pausing thesteering assist control depending on whether an obstacle newly detectedafter the setting/determination of the target path is the moving objector the stationary object, and informing the driver that the steeringassist control is cancelled or paused.

There is provided an embodiment of a steering assist apparatus(hereinafter also referred to as “embodiment apparatus”) applied to anown vehicle. The steering assist apparatus includes:

an information acquiring device (81, 82, 83, 84) configured to acquirevehicle peripheral information including information on an objectpresent in a periphery of the vehicle, and information on a partitionline drawn on a road in the periphery of the vehicle;

a path setting module (10, 10X) configured to set a target region basedon the vehicle peripheral information, and set, as a target path, a pathfor moving the vehicle to the target region, the target region being aregion which is occupied by the vehicle at a time point at which thevehicle completes parking or exiting from a parking space on anassumption that the vehicle moves from a current position of thevehicle; and

a steering assist module (10, 10Y) configured to perform a steeringassist control for changing a steering angle of the vehicle according tothe set target path in such a manner that the vehicle moves along thetarget path.

In a case where the information acquiring device acquires, in a periodfrom a first time point on and after a path setting time point at whichthe target path is set until a second time point at which the vehiclereaches the target region, information on a new object which has notbeen detected at the path setting time point (Step 610:Yes; or Step1710:Yes), the steering assist module is configured to determine whetherthe new object is a stationary object or a moving object based on thevehicle peripheral information (Step 615).

In a case where the steering assist module determines that the newobject is the stationary object (Step 615:Yes), when a cancel conditionis satisfied (Step 620:Yes), the steering assist module is configured tocancel the steering assist control and inform the driver that thesteering assist control is cancelled (Step 625), the cancel conditionbeing a condition which is satisfied when there is a high possibilitythat the new object is an obstacle which obstructs the vehicle when thevehicle travels along the target path.

After a third time point at which the steering assist control iscancelled, the steering assist module is configured not to perform thesteering assist control until the path setting module sets newly thetarget path and sets the target path with respect to the newly settarget region.

In a case where the steering assist module determines that the newobject is the moving object (Step 615:No), when a pause condition issatisfied (Step 635:Yes), the steering assist module is configured topause the steering assist control and inform the driver that thesteering assist control is paused (Step 640), the pause condition beinga condition which is satisfied when there is a high possibility that thenew object is an obstacle which obstructs the vehicle when the vehicletravels along the target path.

In a pause period from a fourth time point at which the pause of thesteering assist control is started until a predetermined time thresholdelapses, when a resume condition is satisfied (Step 720:Yes), thesteering assist module is configured to resume the steering assistcontrol in accordance with the target path used until the fourth timepoint at which the pause of the steering assist control is started (Step730, Step 440), the resume condition being a condition which issatisfied when there is a high possibility that the new object is not anobstacle which obstructs the vehicle when the vehicle travels along thetarget path used until the fourth time point at which the pause of thesteering assist control is started.

The embodiment apparatus cancels or pauses the steering assist controldepending on whether an object newly detected after the setting of thetarget path is the moving object or the stationary object, and informsthe driver that the steering assist control is cancelled or paused. Itis assumed that the newly-detected object is the stationary object, andthere is a high possibility that the stationary object is an obstaclewhich obstructs the traveling of the vehicle when the vehicle travelsalong the target path. In this situation, the steering assist moduleimmediately cancels the steering assist control and informs the driverthat the steering assist control is cancelled. Therefore, the driver canimmediately recognize/notice that the vehicle cannot be parked unlessthe vehicle is moved from the current position to another position. Thedriver can immediately search for (find) another region in which thevehicle can be parked. As a result, the time required for parking thevehicle is shortened as compared to the first related-art apparatus.

It is assumed that the newly-detected object is the moving object, andthere is a high possibility that the moving object is an obstacle whichobstructs the traveling of the vehicle when the vehicle travels alongthe target path. In this situation, the steering assist module pausesthe steering assist control, and informs the driver that the steeringassist control is paused. Therefore, the driver can understand that itis not necessary to move the vehicle from the current position toanother position, and it only has to wait for a while. When thepredetermined resume condition is satisfied while the driver is waiting,the steering assist module resumes the steering assist control inaccordance with the target path used until the fourth time point atwhich the pause of the steering assist control is started. As describedabove, the embodiment apparatus informs/notifies the driver that thesteering assist control is cancelled or paused. The driver canimmediately understand his/her next action (whether to search foranother parking area or wait for a while).

In another aspect of the embodiment apparatus, when the steering assistmodule does not determine that the resume condition is satisfied in thepause period (Step 760:Yes), the steering assist module is configured tocancel the steering assist control at a time point at which the pauseperiod elapses, and inform the driver that the steering assist controlis cancelled (Step 770).

After at a time point at which the steering assist control is cancelled,the steering assist module is configured not to perform the steeringassist control until the path setting module sets newly the target pathand sets the target path with respect to the newly set target region.

It is assumed that the newly-detected object is the moving object, andthat the moving object gets close to the target path, and then is in astopped state near the target path. In this situation, the firstrelated-art apparatus recalculates the target path as described above.However, there is also a high possibility that there is no path thatallows the vehicle to move to the target region without coming intocontact with the obstacle (moving object). For this reason, it is oftennecessary to move the vehicle from the current position to anotherposition. Further, in the first related-art apparatus, the driver has towait for the result of the recalculation of the target path. As aresult, the time required for parking the vehicle becomes longer. On theother hand, in the above situation, the steering assist module accordingto the present aspect immediately cancels the steering assist control atthe time point at which the pause period elapses, and informs the driverthat the steering assist control is cancelled. Therefore, the driver canimmediately search for another region in which the vehicle can beparked. As a result, the time required for parking the vehicle isshortened as compared to the first related-art apparatus.

In another aspect of the embodiment apparatus, in the case where thesteering assist module determines that the new object is the stationaryobject, when at least part of the new object is present within a vehicletraveling area (At), the steering assist module is configured todetermine that the cancel condition is satisfied, the vehicle travelingarea including an area through which a vehicle body of the vehicle isexpected to pass when the vehicle travels along the target path.

In the case where the steering assist module determines that the newobject is the moving object, when either one of a first pause conditionand a second pause condition is satisfied, the steering assist module isconfigured to determine that the pause condition is satisfied, the firstpause condition being a condition which is satisfied when the new objectis moving within the vehicle traveling area, and the second pausecondition being a condition which is satisfied when the new object ismoving toward the vehicle traveling area from an outside of the vehicletraveling area.

The steering assist module according to the present aspect sets thevehicle traveling area, and cancels the steering assist control based onthe positional relationship between the vehicle traveling area and thestationary object. The vehicle traveling area includes the area throughwhich the vehicle body is expected to pass when the vehicle travelsalong the target path. It is assumed that, although the stationaryobject is present within the vehicle traveling area, the stationaryobject is away from the vehicle. In this situation, the secondrelated-art apparatus cancels the steering assist control when thedistance between the vehicle and the stationary object is equal to orless than a predetermined distance. Therefore, a time until the steeringassist control is cancelled becomes longer. Meanwhile, the steeringassist module according to the present aspect immediately cancels thesteering assist control in the above-mentioned situation. The driver canimmediately search for another region in which the vehicle can beparked. As a result, the time required for parking the vehicle isshortened as compared to the second related-art apparatus.

Further, the steering assist module according to the present aspectpauses the steering assist control based on the positional relationshipbetween the vehicle traveling area and the moving object, and the movingdirection of the moving object. It is assumed that, although the movingobject is present within the vehicle traveling area, the moving objectis away from the vehicle. In this situation, the first related-artapparatus pauses the steering assist control when the distance betweenthe vehicle and the moving object is equal to or less than thepredetermined distance threshold. Therefore, the vehicle may get tooclose to the moving object. Meanwhile, the steering assist moduleaccording to the present aspect immediately pauses the steering assistcontrol in the above-mentioned situation. It is possible to prevent thevehicle from getting too close to the moving object.

In another aspect of the embodiment apparatus, when either one of afirst resume condition and a second resume condition is satisfied in thepause period, the steering assist module is configured to determine thatthe resume condition is satisfied, the first resume condition being acondition which is satisfied when the new object is moving in adirection away from the vehicle traveling area at a position outside ofthe vehicle traveling area, and the second resume condition being acondition which is satisfied when the new object is in a stopped stateat a position outside of the vehicle traveling area.

The steering assist module according to the present aspect resumes thesteering assist control based on the positional relationship between thevehicle traveling area and the moving object, and the moving directionof the moving object. It is assumed that, although the moving objectmoves outside of the vehicle traveling area after the steering assistcontrol is paused, the distance between the vehicle and the movingobject is still equal to or less than the predetermined distancethreshold. In this situation, the first related-art apparatus cannotresume the steering assist control as long as the distance between thevehicle and the moving object is equal to or less than the predetermineddistance threshold. Meanwhile, according to the present aspect, sincethe first resume condition is satisfied (that is, the moving object ismoving in a direction away from the vehicle traveling area at a positionoutside of the vehicle traveling area), the steering assist module canimmediately resume the steering assist control. Therefore, a timerequired for resuming the steering assist control is shortened ascompared to the first related-art apparatus.

In another aspect of the embodiment apparatus, the path setting moduleis configured to, when the vehicle cannot move to the target regionthrough one backward movement or one forward movement, set a first path(LtgtA) and a second path (LtgtB) as the target path, the first pathbeing a path for moving the vehicle from the current position to atravel-direction-switching position for switching a travel direction ofthe vehicle, and the second path being a path for moving the vehiclefrom the travel-direction-switching position to the target region.

The path setting module is further configured to set a first vehicletraveling area (At1) and a second vehicle traveling area (At2), thefirst vehicle traveling area including an area through which the vehiclebody is expected to pass when the vehicle travels along the first path,and the second vehicle traveling area including an area through whichthe vehicle body is expected to pass when the vehicle travels along thesecond path.

In the case where the steering assist module determines that the newobject is the moving object,

while the vehicle travels along the first path, when either one of athird pause condition and a fourth pause condition is satisfied, thesteering assist module is configured to determine that the pausecondition is satisfied, the third pause condition being a conditionwhich is satisfied when the new object is moving within the firstvehicle traveling area, and the fourth pause condition being a conditionwhich is satisfied when the new object is moving toward the firstvehicle traveling area from an outside of the first vehicle travelingarea.

Further, in the case where the steering assist module determines thatthe new object is the moving object,

while the vehicle travels along the second path, when either one of afifth pause condition and a sixth pause condition is satisfied, thesteering assist module is configured to determine that the pausecondition is satisfied, the fifth pause condition being a conditionwhich is satisfied when the new object is moving within the secondvehicle traveling area, and the sixth pause condition being a conditionwhich is satisfied when the new object is moving toward the secondvehicle traveling area from an outside of the second vehicle travelingarea.

When a plurality of paths (the first path and the second path) areset/determined as the target path, the steering assist module accordingto the present aspect sets the vehicle traveling area (that is, thefirst vehicle traveling area, the second vehicle traveling area) foreach path. Further, the steering assist module selects the vehicletraveling area according to the path on which the vehicle is currentlytraveling, and determines whether or not the pause condition issatisfied. It is assumed that, when the vehicle moves along the firstpath, although the newly-detected object (moving object) is presentwithin the second vehicle traveling area, the moving object is moving ata position outside of the first vehicle traveling area and in adirection away from the first vehicle traveling area. In this situation,the newly-detected object does not obstruct the traveling of the vehiclewhile the vehicle moves to the travel-direction-switching position.According to the present aspect, since the pause condition is notsatisfied in the above-mentioned situation, the steering assist modulecontinues performing the steering assist control. The steering assistcontrol is not paused unnecessarily, and therefore, it is possible toreduce an opportunity for the driver to feel inconvenience.

Further features relating to the above one or more aspects of theembodiment apparatus become apparent from the description herein and theaccompanying drawings. Problems, configurations, and effects other thanthose described above become apparent from the following description ofembodiments.

In the above description, in order to facilitate understanding of theabove one or more aspect of the embodiment apparatus, a name and/orreference numeral used in embodiments described below is enclosed inparentheses and assigned to each of the constituent featurescorresponding to the embodiments. However, each of the constituentfeatures is not limited to the embodiments defined by the name and/orreference numeral.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram for illustrating a steeringassist apparatus applied to a vehicle according to a first embodiment ofthe present disclosure.

FIG. 2 is a plan view of a vehicle for illustrating an arrangement ofradar sensors, first ultrasonic sensors, second ultrasonic sensors andcameras.

FIG. 3 is a flowchart for illustrating a “routine” to be executed by aCPU of a steering assist ECU illustrated in FIG. 1 .

FIG. 4 is a flowchart for illustrating a “routine” to be executed by theCPU of the steering assist ECU illustrated in FIG. 1 .

FIG. 5 is a flowchart for illustrating a “routine” to be executed by theCPU of the steering assist ECU illustrated in FIG. 1 .

FIG. 6 is a flowchart for illustrating a “routine” to be executed by theCPU of the steering assist ECU illustrated in FIG. 1 .

FIG. 7 is a flowchart for illustrating a “routine” to be executed by theCPU of the steering assist ECU illustrated in FIG. 1 .

FIG. 8 is a plan view for illustrating a situation in which the steeringassist ECU illustrated in FIG. 1 has detected a stationary object.

FIG. 9 is a plan view for illustrating a situation in which the steeringassist ECU illustrated in FIG. 1 has detected a moving object.

FIG. 10 is a plan view for illustrating a situation in which thesteering assist ECU illustrated in FIG. 1 has detected a moving object.

FIG. 11 is a plan view for illustrating a situation in which thesteering assist ECU illustrated in FIG. 1 has detected a moving object.

FIG. 12 is a plan view for illustrating a situation in which thesteering assist ECU illustrated in FIG. 1 has detected a moving object.

FIG. 13 is a plan view for illustrating a situation in which thesteering assist ECU illustrated in FIG. 1 has detected a moving object.

FIG. 14 is a diagram for illustrating images displayed on a touch panelillustrated in FIG. 1 .

FIG. 15 is a diagram for illustrating images displayed on the touchpanel illustrated in FIG. 1 .

FIG. 16 is a diagram for illustrating images displayed on the touchpanel illustrated in FIG. 1 .

FIG. 17 is a flowchart for illustrating a “routine” to be executed bythe CPU of the steering assist ECU according to a second embodiment ofthe present disclosure.

FIG. 18 is a plan view for illustrating a situation in which thesteering assist ECU illustrated in FIG. 1 determines/sets a plurality ofpaths as a target path.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Now, referring to the accompanying drawings, a description is given ofembodiments. The accompanying drawings are illustrations of one or morespecific embodiments in conformity with the principle thereof, but thoseillustrations are mere examples to be used for the understanding of theembodiments, and are not to be used to limit the interpretation of thepresent disclosure.

First Embodiment

A steering assist apparatus (hereinafter also referred to as a “firstapparatus”) according to a first embodiment is applied to a vehicle.Hereinafter, the vehicle equipped with the steering assist apparatusaccording to each embodiment is also referred to as an “own vehicle” inorder to distinguish it from other vehicles.

As illustrated in FIG. 1 , the steering assist apparatus includes asteering assist ECU 10. The steering assist ECU 10 includes amicrocomputer including a CPU 10 a, a RAM 10 b, a ROM 10 c, an interface(I/F) 10 d, and the like. The ECU herein stands for “electric controlunit”. The ECU includes a microcomputer including a CPU, a RAM, a ROM,an interface, and the like. The CPU is configured to executeinstructions (programs and routines) stored in the ROM to implementvarious functions.

The steering assist ECU 10 is connected to an engine ECU 20, a brake ECU30, an electric power steering ECU (hereinafter referred to as an “EPSECU”) 40, a meter ECU 50, a shift-by-wire (SBW) ECU 60 and a navigationECU 70 via a controller area network (CAN) 90. Those ECUs are connectedto one another so as to be capable of mutually transmitting andreceiving information via the CAN 90. Thus, a detection signal obtainedby a sensor connected to a specific ECU of those ECUs is transmitted toECUs other than the specific ECU.

The engine ECU 20 is connected to an engine actuator 21. The engineactuator 21 includes a throttle valve actuator configured to change anopening degree of a throttle valve of an internal combustion engine 22.The engine ECU 20 can change a torque generated by the internalcombustion engine 22 through driving the engine actuator 21. Thus, theengine ECU 20 can control a driving force of the vehicle throughcontrolling the engine actuator 21. When the vehicle is a hybridvehicle, the engine ECU 20 can control a driving force of the vehiclegenerated by any one of or both of “an internal combustion engine and amotor” serving as vehicle driving sources. Further, when the vehicle isan electric vehicle, the engine ECU 20 can control a driving force ofthe vehicle generated by a motor serving as a vehicle driving source.

The brake ECU 30 is connected to a brake actuator 31. A braking force(braking torque) applied to each wheel is controlled by the brakeactuator 31. The brake actuator 31 adjusts a hydraulic pressure ofliquid to be supplied to wheel cylinders integrated into brake calipers32 b in accordance with an instruction from the brake ECU 30, so as touse the hydraulic pressure to press brake pads against brake discs 32 a,to thereby generate friction braking forces. Thus, the brake ECU 30 cancontrol the braking force of the vehicle through controlling the brakeactuator 31.

The EPS ECU 40 is connected to an assist motor (M) 41. The assist motor41 is integrated into a “steering mechanism including a steering wheel,a steering shaft coupled to the steering wheel, and a gear mechanism forsteering” (not shown) of the vehicle. The EPS ECU 40 uses a steeringtorque sensor (not shown) provided in the steering shaft to detect asteering torque input to the steering wheel by the driver, to therebydrive the assist motor 41 based on the steering torque. The EPS ECU 40applies a steering torque (steering assist torque) to the steeringmechanism through the drive of the assist motor 41, to thereby assist asteering operation of the driver.

Further, when the EPS ECU 40 receives a steering command from thesteering assist ECU 10 via the CAN 90 during the steering assist controldescribed later, the EPS ECU 40 drives the assist motor 41 based on thesteering torque represented by the steering command. This steeringtorque is different from the above-mentioned steering assist torqueapplied for reducing the load of the steering operation (steering wheeloperation) of the driver, and therefore, is a torque applied to thesteering mechanism in response to the steering command from the steeringassist ECU 10 without requiring the steering operation of the driver.With this torque, a steering angle of steered wheels of the vehicle ischanged (that is, the steered wheels are steered).

The meter ECU 50 is connected to a display device 51 and a vehicle speedsensor 52. The display device 51 is a multi-information display providedin front of a driver's seat. The vehicle speed sensor 51 detects a speed(traveling speed) of the vehicle and outputs a detection signal or anoutput signal indicative of the traveling speed. The display device 51displays various types of information in addition to measurement valuessuch as the traveling speed and an engine revolution speed. A head-updisplay may be employed as the display device 51. The vehicle speedsensor 51 transmits the detected traveling speed to the steering assistECU 10.

The SBW ECU 60 is connected to a shift position sensor 61. The shiftposition sensor 61 detects a position of a shift lever serving as amovable portion of a shift operation unit. In this example, positions ofthe shift lever include a parking position (P), a drive position (D),and a reverse position (R). The SBW ECU 60 is configured to receive theposition of the shift lever from the shift position sensor 61 to controla transmission and/or driving-direction switching mechanism (not shown)of the vehicle based on the shift lever position. That is, the SBW ECUis configured to perform a shift control for the own vehicle. Morespecifically, when the position of the shift lever is “P”, the SBW ECU60 controls the transmission and/or driving-direction switchingmechanism in such a manner that the driving force is not transmitted todrive wheels and the vehicle is thus mechanically locked to a stopposition. When the position of the shift lever is “D”, the SBW ECU 60controls the transmission and/or driving-direction switching mechanismin such a manner that the driving force for moving the vehicle forwardis transmitted to the drive wheels. Further, when the position of theshift lever is “R”, the SBW ECU 60 controls the transmission and/ordriving-direction switching mechanism in such a manner that the drivingforce for moving the vehicle backward is transmitted to the drivewheels. The SBW ECU 60 is configured to output to the steering assistECU 10 a signal indicative of the position of the shift lever receivedfrom the shift position sensor 61.

The navigation ECU 70 includes a GPS receiver 71 configured to receive aGPS signal for detecting “a latitude and a longitude” at a currentposition of the vehicle, a map database 72 having map information storedtherein, a touch panel (touch-panel-type display device) 73, and thelike. The map information stored in the map database 72 includes roadinformation. For example, in the road information, the number of lanesincluded in a road, the width of the road, a gradient of the road, andthe like are associated with each road section. The navigation ECU 70executes various calculation processes based on the latitude and thelongitude at a current position of the vehicle, the map information, andthe like to cause the touch panel 73 to display the position of thevehicle on the map. Hereinafter, a display mode when the map and theposition of the vehicle on the map are displayed on the touch panel 73is referred to as a “navigation mode”.

Further, the display mode of the touch panel 73 includes a steeringassist mode in addition to the navigation mode. The steering assist modeis a display mode displayed when performing the steering assist controlfor parking the vehicle or exiting the vehicle from the parking space. Ahome button (not shown) is provided adjacent to the touch panel 73. Whenthe display mode is the steering assist mode, as the driver depressesthe home button, the display mode is switched to the navigation mode.

A plurality of radar sensors 81 a to 81 e, a plurality of firstultrasonic sensors 82 a to 82 d, a plurality of second ultrasonicsensors 83 a to 83 h, a plurality of cameras 84 a to 84 d, a steeringassist switch 85, and a speaker 86 are connected to the steering assistECU 10. The plurality of radar sensors 81 a to 81 e are generallyreferred to as “radar sensors 81”. The plurality of first ultrasonicsensors 82 a to 82 d are generally referred to as “first ultrasonicsensors 82”. The plurality of second ultrasonic sensors 83 a to 83 h aregenerally referred to as “second ultrasonic sensors 83”. The pluralityof cameras 84 a to 84 d are generally referred to as “cameras 84”.

Each of the radar sensors 81 includes a radar transceiver (radartransmitting/receiving part) (not shown) and a signal processor (notshown). The radar transceiver radiates a radio wave in a millimeterwaveband (hereinafter referred to as a “millimeter wave”), and receivesa millimeter wave (that is, reflected wave) reflected by an object(e.g., other vehicles, pedestrian, bicycle, and building) present withina radiation range. The signal processor acquires object informationbased on, for example, a phase difference between the transmittedmillimeter wave and the received reflected wave, an attenuation level ofthe reflected wave, and a time period required from transmission of themillimeter wave to reception of the reflected wave. The objectinformation includes, for example, a distance between the vehicle andthe object, a relative speed between the vehicle and the object, and arelative position (direction) of the object with respect to the vehicle.The signal processor transmits the object information as the detectionsignal to the steering assist ECU 10.

As illustrated in FIG. 2 , the radar sensor 81 a is disposed at afront-right corner portion of a vehicle body 200 of the vehicle 100, andmainly acquires the object information on an object present in afront-right region of the vehicle. The radar sensor 81 b is disposed ata front-center portion of the vehicle body 200, and mainly acquires theobject information on an object present in a front region of thevehicle. The radar sensor 81 c is disposed at a front-left cornerportion of the vehicle body 200, and mainly acquires the objectinformation on an object present in a front-left region of the vehicle.The radar sensor 81 d is disposed at a rear-right corner portion of thevehicle body 200, and mainly acquires the object information on anobject present in a rear-right region of the vehicle. The radar sensor81 e is disposed at a rear-left corner portion of the vehicle body 200,and mainly acquires the object information on an object present in arear-left region of the vehicle.

Each of the first ultrasonic sensors 82 and the second ultrasonicsensors 83 (hereinafter generally referred to as “ultrasonic sensors”when these sensors are not required to be distinguished from each other)transmits an ultrasonic wave having a pulse form in a predeterminedrange, and receives a reflected wave reflected by an object. Theultrasonic sensor detects, based on a period from the transmission ofthe ultrasonic wave to the reception of the ultrasonic wave, a distancebetween a reflection point which is a point of an object by which thetransmitted ultrasonic wave is reflected, and the ultrasonic sensor.Hereinafter, this distance is referred to as a “reflection-pointdistance”.

The first ultrasonic sensors 82 are used to detect an object at aposition relatively far from the vehicle compared with the secondultrasonic sensors. As illustrated in FIG. 2 , the first ultrasonicsensor 82 a is mounted at a position on the right side of the front partof the vehicle body 200 (for example, an end on the right side of afront bumper 201), and detects the reflection-point distance withrespect to an object present on the right side of the front side of thevehicle. The first ultrasonic sensor 82 b is mounted at a position onthe left side of the front part of the vehicle body 200 (for example, anend on the left side of the front bumper 201), and detects thereflection-point distance with respect to an object present on the leftside of the front side of the vehicle. The first ultrasonic sensor 82 cis mounted at a position on the right side of the rear part of thevehicle body 200 (for example, an end on the right side of a rear bumper202), and detects the reflection-point distance with respect to anobject present on the right side of the rear side of the vehicle.Further, the first ultrasonic sensor 82 d is mounted at a position onthe left side of the rear part of the vehicle body 200 (for example, anend on the left side of the rear bumper 202), and detects thereflection-point distance with respect to an object present on the leftside of the rear side of the vehicle.

The second ultrasonic sensors 83 are used to detect an object at aposition relatively close to the vehicle. As illustrated in FIG. 2 , thefour second ultrasonic sensors 83 a to 83 d are mounted to the frontbumper 201 at intervals in a vehicle widthwise direction. The secondultrasonic sensors 83 a to 83 d detect the reflection-point distancewith respect to an object in front of the vehicle. Further, the foursecond ultrasonic sensors 83 e to 83 h are mounted to the rear bumper202 at intervals in the vehicle widthwise direction. The secondultrasonic sensors 83 e to 83 h detect the reflection-point distancewith respect to an object in the back of the vehicle.

Each of the plurality of cameras 84 a to 84 d is a digital cameraincorporating an image pickup device such as a charge coupled device(CCD) and a CMOS image sensor (CIS). Each of the cameras 84 a to 84 doutputs image data at a predetermined frame rate. An optical axis ofeach of the cameras 84 a to 84 d is set obliquely downward from thevehicle body of the vehicle. Thus, each of the cameras 84 a to 84 dpicks up an image of a peripheral state of the vehicle to be checkedwhen the vehicle is parked or exits from the parking space, and outputsdata on the obtained image to the steering assist ECU 10. This data onthe peripheral state of the vehicle includes the positions and shapes ofpartition lines, three-dimensional objects, a parking-possible region inwhich the vehicle can be parked, and the like.

As illustrated in FIG. 2 , the camera 84 a is mounted to substantially acenter part of the front bumper 201 in the vehicle widthwise direction,and acquires image data in front of (ahead of) the vehicle. The camera84 b is mounted to a wall part of a rear trunk 203 in the rear part ofthe vehicle body 200, and acquires image data in the back of thevehicle. The camera 84 c is mounted to a door mirror 204 on a right sideof the vehicle, and acquires image data on the right side of thevehicle. The camera 84 d is mounted to a door mirror 205 on a left sideof the vehicle, and acquires image data on the left side of the vehicle.

The steering assist ECU 10 receives the detection signal from each ofthe radar sensors 81, the first ultrasonic sensors 82 and the secondultrasonic sensors 83 every time a predetermined period elapses. Thispredetermined period is referred to as a “first predetermined period”for the sake of convenience. The steering assist ECU 10 plotsinformation (that is, the object information, the reflection point, andthe reflection-point distance) included in the detection signal on atwo-dimensional map. This two-dimensional map is a plan view in whichthe current position of the vehicle is defined as the origin, the traveldirection of the vehicle is defined as the X-axis, and the leftdirection of the vehicle is defined as the Y-axis. The position of thevehicle is the center position of a left front wheel and a right frontwheel in the plan view. The position of the vehicle may be anotherspecific position on the vehicle (for example, the position of thecenter of gravity of the vehicle in the plan view or a geometric centerposition of the vehicle in the plan view).

The steering assist ECU 10 acquires the image data from each of thecameras 84 every time the first predetermined period elapses. Thesteering assist ECU 10 analyzes the image data from each of the cameras84 to thereby detect an object which is present in the periphery of theown vehicle. Further, the steering assist ECU 10 determines/specifiesthe position and shape of the object with respect to the vehicle.Information on the position of the object includes a distance from thevehicle, and an azimuth direction of the object with respect to thevehicle. Further, the steering assist ECU 10 detects partition lines(including partition lines for defining a lane, and partition lines fordefining a parking area) drawn/painted on a road surface around thevehicle in the image data from each of the cameras 84. The steeringassist ECU 10 determines/specifies the positions and shapes of thepartition lines with respect to the vehicle. Information on the positionof each partition line includes a distance from the vehicle to thatpartition line, and an azimuth direction of that partition line withrespect to the vehicle. The steering assist ECU 10 draws the object andthe partition lines specified (detected) based on the image data on theabove-described two-dimensional map.

The steering assist ECU 10 recognizes/detects the object present in theperiphery of the vehicle (within a predetermined distance range from theposition of the vehicle) based on the information shown on thetwo-dimensional map, and also detects a “region where no object ispresent” in the periphery of the vehicle. When the detected region is aregion having a size and shape sufficient to park the vehicle (or exitthe vehicle from the parking space), the steering assist ECU 10determines the detected region as a “candidate region”. For example, thecandidate region is a rectangle which does not cross the detectedpartition lines. The rectangle has a long side which is longer than alongitudinal length of the vehicle by a first margin, and a short sidewhich is longer than a length in a right-left direction of the vehicleby a second margin.

The radar sensors 81, the first ultrasonic sensors 82, the secondultrasonic sensors 83 and the cameras 84 are generally referred to as“vehicle peripheral sensors”. Information obtained based on the signalsfrom the vehicle peripheral sensors is referred to as “vehicleperipheral information”. The vehicle peripheral information includesinformation (position and shape, etc.) on the object present in theperiphery of the vehicle, and information (position and shape, etc.) onthe partition line drawn on the road in the periphery of the vehicle.

The steering assist switch 85 is a switch to be operated (pressed ordepressed) when the driver requests the steering assist ECU 10 toperform the steering assist control. In the present specification, thesteering assist control is a well-known control for automaticallysteering the steering wheel to automatically change the steering anglewhen the vehicle is parked (or when the vehicle is caused to exit from aparking space). Therefore, a parking operation (orexit-from-parking-space operation) of the driver is assisted/supported.In addition, the steering assist control is also referred to as “IPA(Intelligent Parking Assist)”. The steering assist control has one ormore steering assist modes described later.

The speaker 86 produces/generates a sound when the speaker 86 receives asound command from the steering assist ECU 10.

(Summary of Operation)

When the steering assist ECU 10 causes the vehicle on a road to beparked at a predetermined region in accordance with a perpendicularparking or a parallel parking to be described later, or causes thevehicle parked by the parallel parking to be moved from the parkingspace to a predetermined region on a road (that is, causes the vehicleto be exited from the parking space), the steering assist ECU 10sets/determines a target path. Then, the steering assist ECU 10 performsan automatic steering control (that is, steering assist control) forautomatically changing the steering angle of the vehicle in accordancewith the target path. In this manner, the steering assist ECU 10includes a “target path setting module (target path setting unit) 10Xconfigured to set/determine the target path” implemented by the CPU 10 ain terms of function. The steering assist ECU 10 further includes a“steering assist module (steering assist unit) 10Y configured to performthe automatic steering control (steering assist control) for changingthe steering angle of the vehicle in accordance with the target path”implemented by the CPU 10 a in terms of function.

After the automatic steering control is started, when the steeringassist ECU 10 detects a new object which has not been detected at thetime point at which the target path is set/determined, the steeringassist ECU 10 determines whether the newly-detected object is a movingobject or a stationary object (motionless object). The steering assistECU 10 determines whether to satisfy a condition (a cancel position or apause condition to be described later) depending on whether thenewly-detected object is the moving object or the stationary object.When the condition is satisfied, the steering assist ECU 10 cancels(aborts) the automatic steering control before completion of thatcontrol, or pauses (temporally stops/suspends) the automatic steeringcontrol.

When the steering assist ECU 10 cancels the automatic steering control,the steering assist ECU 10 discards the target region and the targetpath (that is, erases/removes the target region and the target path fromthe RAM) at the time point at which the automatic steering control iscancelled. Therefore, the automatic steering control is not performeduntil the vehicle is moved to another location to thereby set/determinea new target region and a new target path. On the other hand, when thesteering assist ECU 10 pauses the automatic steering control, thesteering assist ECU 10 maintains (holds) the target region and thetarget path on and after the time point at which the pause of theautomatic steering control is started. When a resume condition describedlater is satisfied, the steering assist ECU 10 resumes the automaticsteering control by using the target region and the target path whichhave been maintained/held from the time point at which the pause of theautomatic steering control is started.

The perpendicular parking is a parking operation of parking the ownvehicle in a direction perpendicular to a travel direction of a road.The perpendicular parking is synonymous with parking the own vehicle inparallel to other parked vehicles. More specifically, the perpendicularparking is an operation of parking the own vehicle in such a manner thatone side surface of the own vehicle is opposed to one side surface ofanother vehicle (first another vehicle), the other side surface of theown vehicle is opposed to one side surface of still another vehicle(second another vehicle), and a longitudinal axis passing through thecenter in the widthwise direction of the own vehicle and longitudinalaxes passing through the centers in the widthwise direction of the firstand second another vehicles are parallel to each other. Theperpendicular parking may be an operation of parking the own vehicle insuch a manner that the own vehicle is parked in the directionperpendicular to the travel direction of the road, and at least one ofthe left and right side surfaces of the own vehicle is opposed to awhite line, a wall, a fence, a guard rail, or the like.

The parallel parking is a parking operation of parking the own vehiclein a direction parallel to the travel direction of the road. Theparallel parking is synonymous with parking the own vehicle to be linewith other vehicles parked along the travel direction of the road. Morespecifically, the parallel parking is an operation of parking the ownvehicle in such a manner that the front end portion of the own vehicleis opposed to the rear end portion (or front end portion) of the firstanother vehicle, the rear end portion of the own vehicle is opposed tothe front end portion (or rear end portion) of the second anothervehicle, and the longitudinal axis passing through the center in thewidthwise direction of the own vehicle and the longitudinal axes passingthrough the centers in the widthwise direction of the first and secondanother vehicles are substantially on the same line.

The steering assist ECU 10 monitors the operation of the driver withrespect to steering assist switch 85, the position of the shift leverand the vehicle speed to determine whether or not a steering assistrequest is made/generated as described below. The steering assistrequest includes a perpendicular parking assist request, a parallelparking assist request, and an exit-from-parking-space assist request.When it is determined that the steering assist request is made, thedisplay mode of the touch panel 73 is automatically changed to thesteering assist mode.

Every time the steering assist switch 85 is depressed, the steeringassist ECU 10 switches a switch mode to a perpendicular parking mode, aparallel parking mode, an exit-from-parking-space mode, and anon-setting mode in this order. For example, when the steering assistswitch 85 is depressed once in a situation in which the switch mode isthe non-setting mode, the switch mode is switched/changed to theperpendicular parking mode. When the steering assist switch 85 isdepressed twice in the situation in which the switch mode is thenon-setting mode, the switch mode is switched/changed to the parallelparking mode. When the steering assist switch 85 is depressed threetimes in the situation in which the switch mode is the non-setting mode,the switch mode is switched/changed to the exit-from-parking-space mode.When the steering assist switch 85 is depressed three times in asituation in which the switch mode is the perpendicular parking mode,the switch mode is switched/changed to the non-setting mode. Thesteering assist switch 85 may be a rotary or dial type switch. In thisconfiguration, the switch mode may be switched between the perpendicularparking mode, the parallel parking mode, the exit-from-parking-spacemode, and the non-setting mode depending on the rotational position ofthe steering assist switch 85.

<Perpendicular Parking Assist Request>

When all of the following conditions A1 to A5 are satisfied, thesteering assist ECU 10 determines that the perpendicular parking assistrequest is made.

(Condition A1) The steering assist request (the perpendicular parkingassist request, the parallel parking assist request, and theexit-from-parking-space assist request) has not been yet made/generated.

(Condition A2) the perpendicular parking mode is selected through apredetermined operation (one depression operation) of the steeringassist switch 85.

(Condition A3) The position of the shift lever is the driving position(D) at the time point at which the condition A2 is satisfied.

(Condition A4) The vehicle speed is equal to or lower than apredetermined low speed threshold (for example, 30 km/h) at the timepoint at which the condition A2 is satisfied.

(Condition A5) The candidate region for the perpendicular parking hasbeen detected. This region is also referred to as a“perpendicular-parking candidate region”. The candidate region is aregion adjacent to a road in which the vehicle travels, and the minimumdistance from the current position of the vehicle to that candidateregion is equal to or shorter than a predetermined distance. Inaddition, the candidate region has a size and shape sufficient to parkthe vehicle thereto through the perpendicular parking mode.

<Parallel Parking Assist Request>

When all of the following conditions B1 to B5 are satisfied, thesteering assist ECU 10 determines that the parallel parking assistrequest is made.

(Condition B1) The steering assist request (the perpendicular parkingassist request, the parallel parking assist request, and theexit-from-parking-space assist request) has not been yet made/generated.

(Condition B2) the parallel parking mode is selected through apredetermined operation (two consecutive depression operation) of thesteering assist switch 85.

(Condition B3) The position of the shift lever is the driving position(D) at the time point at which the condition B2 is satisfied.

(Condition B4) The vehicle speed is equal to or lower than thepredetermined low speed threshold (for example, 30 km/h) at the timepoint at which the condition B2 is satisfied.

(Condition B5) The candidate region for the parallel parking has beendetected. This region is also referred to as a “parallel-parkingcandidate region”. The candidate region is a region adjacent to a roadin which the vehicle travels, and the minimum distance from the currentposition of the vehicle to that candidate region is equal to or shorterthan the predetermined distance. In addition, the candidate region has asize and shape sufficient to park the vehicle thereto through theparallel parking mode.

<Exit-from-Parking-Space Assist Request>

When all of the following conditions C1 to C5 are satisfied, thesteering assist ECU 10 determines that the exit-from-parking-spaceassist request is made.

(Condition C1) The steering assist request (the perpendicular parkingassist request, the parallel parking assist request, and theexit-from-parking-space assist request) has not been yet made/generated.

(Condition C2) the exit-from-parking-space mode is selected through apredetermined operation (three consecutive depression operation) of thesteering assist switch 85.

(Condition C3) The position of the shift lever is the parking position(P) at the time point at which the condition C2 is satisfied.

(Condition C4) The vehicle speed is equal to a predetermined stop speedthreshold (for example, 0 km/h) at the time point at which the conditionC2 is satisfied.

(Condition C5) The candidate region for exiting the vehicle from theparking space has been detected. This candidate region is referred to asan “exit-from-parking-space candidate region”. The candidate region is aregion of a road adjacent to the parking space in which the vehicle isparked, and has a size and shape sufficient to move the vehicle theretothrough the exit-from-parking-space mode.

When the perpendicular parking assist request is made, the steeringassist ECU 10 performs the automatic steering control (steering assistcontrol) for parking the vehicle in a predetermined region in theperpendicular-parking candidate region.

When the parallel parking assist request is made, the steering assistECU 10 performs the automatic steering control (steering assist control)for parking the vehicle in a predetermined region in theparallel-parking candidate region.

When the exit-from-parking-space assist request is made, the steeringassist ECU 10 performs the automatic steering control (steering assistcontrol) for moving the vehicle to a predetermined region in theexit-from-parking-space candidate region.

The above-mentioned automatic steering controls (steering assistcontrols) are similar to each other except that regions (target regions)to which the vehicle is to be finally moved are different from eachother. In the following, for simplicity of explanation, it is assumedthat the steering assist ECU 10 is configured to perform only theautomatic steering control for the perpendicular parking assist request.By this assumption, the above condition A1 is satisfied when theperpendicular parking request has not been yet made/generated.

(Procedure)

Every time a “second predetermined period longer than the firstpredetermined period” elapses, the CPU 10 a (hereinafter simply referredto as a “CPU”) of the steering assist ECU 10 is configured to executeroutines illustrated in FIGS. 3 to 5 , respectively. Further, asdescribed above, the CPU executes a routine (not shown), every time thefirst predetermined period elapses, to update the above-mentionedtwo-dimensional map based on the vehicle peripheral information.

Further, when an ignition switch (not shown) of the vehicle is changedfrom an OFF state to an ON state, the CPU executes an initializationroutine (not shown) to set various flags described later to “0”. Theignition switch is also referred to as a “start switch”.

(Automatic Steering Control)

The CPU starts processing from Step 300 of FIG. 3 at a predeterminedtiming, and proceeds to Step 310 to determine whether or not a value ofa perpendicular parking assist request flag FHS is “0”. Hereinafter, theperpendicular parking assist request flag is simply referred to as a“request flag”. When the value of the request flag FHS is “0”, thisindicates that the perpendicular parking assist request has not yet beenmade/generated at the current time point. When the value of the requestflag FHS is “1”, this indicates that the perpendicular parking assistrequest has already been made/generated. Therefore, at Step 310, the CPUdetermines whether or not the condition A1 is satisfied. When the valueof the request flag FHS is not “0”, the CPU makes a “No” determinationat Step 310, and proceeds directly to Step 395 to tentatively terminatethe present routine.

It is assumed that the value of the request flag FHS is “0”. In thiscase, the CPU makes a “Yes” determination at Step 310, and proceeds toStep 320. At Step 320, the CPU determines whether or not theperpendicular parking mode is selected through the predeterminedoperation of the steering assist switch 85 (that is, whether or not thecondition A2 is satisfied). When the perpendicular parking mode is notselected, the CPU makes a “No” determination at Step 320, and proceedsdirectly to Step 395 to tentatively terminate the present routine.

It is assumed that the perpendicular parking mode is selected. In thiscase, the CPU makes a “Yes” determination at Step 320, and proceeds toStep 330 to determine whether or not all of the conditions A3, A4 and A5are satisfied. The conditions A3, A4 and A5 are collectively referred toas a “perpendicular-parking execution condition”. When theperpendicular-parking execution condition is not satisfied, the CPUmakes a “No” determination at Step 330, and proceeds directly to Step395 to tentatively terminate the present routine.

It is assumed that the perpendicular-parking execution condition issatisfied. In this case, the CPU makes a “Yes” determination at Step330, and sequentially executes the following processes of Steps 340 and350, and then, proceeds to Step 360.

Step 340: the CPU sets the value of the request flag FHS to “1”.

Step 350: for each of parallel-parking candidate regions which have beendetected, the CPU sets, as a tentative target region, a region occupiedby the vehicle body of the vehicle when it is assumed that the vehicleis parked in the parallel-parking candidate region. Further, for eachtentative target region, the CPU sets, as a tentative target position,the position of the vehicle (the center position of the left front wheeland the right front wheel in the plan view) when it is assumed that thevehicle is parked in the tentative target region.

In addition, at Step 350, for each tentative target position, the CPUcalculates, as a tentative target path, a path for moving the vehiclefrom the current position of the vehicle to the tentative targetposition. The target path is a path along which the vehicle can movefrom the current position to the target position while a predeterminedclearance or more is provided/secured between the vehicle body of thevehicle and objects (for example, other vehicles, curbs, or guardrails). Therefore, the CPU sets/determines, as the tentative targetpath, a path for moving the vehicle from the current position to thetentative target region while maintaining the distance between thevehicle body of the vehicle and the objects at the predeterminedclearance (margin clearance) or more. Depending on the situation, theremay arise cases where the tentative target path cannot be set/obtained.Various methods are known to calculate the target path, and any one ofthe methods may be selected. For example, a calculation method for thetarget path proposed in Japanese Patent Application Laid-open No.2015-3565 may be employed. When two or more tentative target paths areset/obtained, the CPU sets/determines, as a final target path, a pathhaving the shortest distance among the tentative target paths.

For example, in an example illustrated in FIG. 8 , the vehicle 100 ispresent at a current position Pnow, and there are parking areas 302partitioned by a plurality of partition lines (parking area lane marks)301 in the periphery of the vehicle 100. The CPU has detected an othervehicle Vot as the object. The CPU has recognized that there are aperpendicular-parking candidate region As1 and a perpendicular-parkingcandidate region As2 in the periphery of the vehicle 100.

When the CPU proceeds to Step 350 in the routine of FIG. 3 in theabove-mentioned situation, the CPU sets a tentative target region Fp1 inthe perpendicular-parking candidate region As1. The CPU sets/determines,as a tentative target position Ptgt1, the position of the vehicle 100 atthe time of completion of the perpendicular parking on the assumptionthat the vehicle 100 is parked in the tentative target region Fp1. TheCPU calculates, as a tentative target path Ltgt1, a path for moving thevehicle 100 from the current position Pnow of the vehicle 100 to thetentative target position Ptgt1. In the same way, the CPU sets atentative target region Fp2 in the perpendicular-parking candidateregion As2. The CPU sets/determines, as a tentative target positionPtgt2, the position of the vehicle 100 at the time of completion of theperpendicular parking on the assumption that the vehicle 100 is parkedin the tentative target region Fp2. The CPU calculates, as a tentativetarget path Ltgt2, a path for moving the vehicle 100 from the currentposition Pnow of the vehicle 100 to the tentative target position Ptgt2.Next, the CPU sets/determines, as a final target path Ltgt, the pathLtgt1 having the shortest distance among the tentative target pathsLtgt1 and Ltgt2. Therefore, the CPU sets/determines the tentative targetregion Fp1 as a final target region, and sets/determines the tentativetarget position Ptgt1 as a final target position Ptgt.

Next, the CPU proceeds to Step 360 in the routine of FIG. 3 to determinewhether or not the final target path can be set (obtained/calculated).When the final target path cannot be set, the CPU makes a “No”determination at Step 360, and proceeds directly to Step 395 totentatively terminate the present routine. In this case, the CPU maydisplay a message: “PLEASE MOVE VEHICLE TO ANOTHER LOCATION” on a screen(for example, the touch panel 73), and return to Step 350. Further, theCPU may cause the speaker 86 to speak the message displayed on thescreen.

Meanwhile, when the final target path can be set, the CPU sequentiallyexecutes the following processes of Steps 370 to 390, and then, proceedsto Step 395 to tentatively terminate the present routine.

Step 370: The CPU stores the final target region, the final targetposition and the final target path in the RAM 10 b.

Step 380: The CPU sets/determines a steering angle pattern, and thedirection in which the vehicle 100 is to be moved (specifically, theposition of the shift lever) for moving the vehicle along the finaltarget path”, and stores data on the steering angle pattern and theposition of the shift lever in the RAM 10 b. The steering angle patternis data that associates each position of the own vehicle on the targetpath with the steering angle of the vehicle at each position, and thusrepresents a change in the steering angle while the vehicle travelsalong the target path.

Step 390: The CPU sets a perpendicular parking assist execution flag FHEto “1”. Hereinafter, the perpendicular parking assist execution flag issimply referred to as an “execution flag”.

As described above, when the perpendicular parking assist request ismade (that is, all of the conditions A1 to A5 are satisfied), the CPUsets/determines the final target region, the final target position andthe final target path, and sets/determines the steering angle pattern,and the direction in which the vehicle 100 is to be moved. Further, theCPU sets the value of the execution flag FHE to “1”. Hereinafter, “dataon the target region, the target position, the target path, thedirection in which the vehicle 100 is to be moved, and the steeringangle pattern” are collectively referred to as “steering assist data”.

The CPU starts processing from Step 400 of FIG. 4 at a predeterminedtiming, and proceeds to Step 410 to determine whether or not the valueof the execution flag FHE is “1”. When the value of the execution flagFHE is not “1”, the CPU makes a “No” determination at Step 410, andproceeds directly to Step 495 to tentatively terminate the presentroutine.

Meanwhile, when the value of the execution flag FHE is “1”, the CPUmakes a “Yes” determination at Step 410, and proceeds to Step 420 todisplay a guidance relating to the steering assist control for theperpendicular parking on the screen (the touch panel 73). Hereinafter,the steering assist control for the perpendicular parking is simplyreferred to as “perpendicular parking assist control”. Morespecifically, based on the current position of the vehicle, the CPUdisplays the direction in which the vehicle is to be moved(specifically, the position of the shift lever) on the screen. Forexample, when the vehicle is to be moved backward from the currentposition along the target path, the CPU displays, on the screen, aguidance that the vehicle is to be moved backward (that is, a guidancefor moving the position of the shift lever to the reverse position (R)).See a message 1003 illustrated in FIG. 14 described later.

Next, the CPU proceeds to Step 430 to determine whether or not thecurrent position of the shift lever is the position displayed on thescreen (position corresponding to the direction in which the vehicle isto be moved). When the current position of the shift lever is not theposition displayed on the screen, the CPU makes a “No” determination atStep 430, and proceeds directly to Step 495 to tentatively terminate thepresent routine.

Meanwhile, when the current position of the shift lever is the positiondisplayed on the screen, the CPU makes a “Yes” determination at Step430, and proceeds to Step 440 to transmit a steering control signal(including a target steering angle) to the EPS ECU 40 in accordance withthe steering angle pattern. The EPS ECU 40 drives the assist motor 41 inaccordance with the steering control signal to make the actual steeringangle of the vehicle match up with (become equal to) the target steeringangle. As a result of the automatic steering control (steering assistcontrol) being performed in this manner, it is possible to move thevehicle to the target region (that is, the target position) withoutoperating the steering wheel by the driver. As described above, the CPUperforms the perpendicular parking assist control at Step 440.

Further, the CPU starts processing from Step 500 of FIG. 5 at apredetermined timing, and proceeds to Step 510 to determine whether ornot the value of the request flag FHS is “1”. When the value of therequest flag FHS is not “1”, the CPU makes a “No” determination at Step510, and proceeds directly to Step 595 to tentatively terminate thepresent routine.

When the value of the request flag FHS is “1”, the CPU makes a “Yes”determination at Step 510, and proceeds to Step 520 to determine whetheror not the position of the vehicle has reached the final target position(the vehicle has reached the final target region). When the position ofthe vehicle has not yet reached the final target position, the CPU makesa “No” determination at Step 520, and proceeds directly to Step 595 totentatively terminate the present routine.

On the other hand, when the position of the vehicle has reached thefinal target position, the CPU makes a “Yes” determination at Step 520.Next, the CPU sequentially executes the following processes of Steps 530and 540, and then, proceeds to Step 595 to tentatively terminate thepresent routine.

Step 530: the CPU executes a termination process for the perpendicularparking assist control. More specifically, the CPU displays on thescreen a message that the perpendicular parking assist control isfinished/completed. Further, the CPU transmits a brake control signal tothe brake ECU 30 to generate the braking force to thereby stop thevehicle at the target position. In addition, the CPU removes/erases thesteering assist data from the RAM 10 b.

Step 540: the CPU sets the request flag FHS, the execution flag FHE, anda perpendicular parking assist pause flag FHP to “0”, respectively.Hereinafter, the perpendicular parking assist pause flag is simplyreferred to as a “pause flag”.

(Cancel Process/Pause Process)

When the CPU has detected a new object around the vehicle while theautomatic steering control is being performed in accordance with thesteering assist data, the CPU is configured to cancel or pause theperpendicular parking assist control. More specifically, every time thesecond predetermined period elapses, the CPU is configured to executeroutines illustrated in FIGS. 6 and 7 , respectively.

The CPU starts processing from Step 600 of FIG. 6 at a predeterminedtiming, and proceeds to Step 605 to determine whether or not all of thefollowing conditions D1 to D3 are satisfied.

(Condition D1): the value of the request flag FHS is “1”.

(Condition D2): the value of the execution flag FHS is “1”.

(Condition D3): the value of the pause flag FHP is “0”.

When one or more of the conditions D1 to D3 are not satisfied, the CPUmakes a “No” determination at Step 605, and proceeds directly to Step695 to tentatively terminate the present routine.

Meanwhile, when all of the conditions D1 to D3 are satisfied, the CPUmakes a “Yes” determination at Step 605, and proceeds to Step 610. AtStep 610, the CPU determines whether or not a new object is detected inthe periphery of the vehicle based on the vehicle peripheral informationafter the start of the automatic steering control of Step 440.Specifically, the term “new object” means an object which has not yetbeen detected at a time point at which the CPU sets/determines thesteering assist data (including the final target region, the finaltarget position, the final target path, and the like). Hereinafter, the“time point at which the CPU sets/determines the steering assist data”is also referred to as a “path setting time point (or path determinationtime point)”. In other words, the “new object” is an object which hasbeen detected in a “specific period from a first time point on and afterthe path setting time point (that is, the time point at which theautomatic steering control according to the steering angle pattern isstarted) to a second time point at which the position of the vehiclereaches the target position (that is, the vehicle reaches the targetregion)”. As described above, the CPU determines whether or not a newobject has been detected in the specific period. At Step 610, the CPUdetermines whether or not a new object has been detected based on thetwo-dimensional map created at a time point (hereinafter also referredto as “first detection time point”) immediately before this time pointof executing the processing of Step 610. When a new object has not beendetected, the CPU makes a “No” determination at Step 610, and proceedsdirectly to Step 695 to tentatively terminate the present routine.

On the other hand, when a new object has been detected, the CPU makes a“Yes” determination at Step 610, and proceeds to Step 615 to determinewhether or not the new object is the stationary object (motionlessobject). That is, the CPU determines whether the new object is thestationary object or the moving object.

More Specifically, the CPU calculates a moving speed of the new objectand a moving direction of the new object based on:

(i) the two-dimensional map created at a time point (hereinafter alsoreferred to as “the second detection time point”) before the firstpredetermined period from the first detection time point;

(ii) the two-dimensional map created at the first detection time point;

(iii) a movement amount of the vehicle in a period from the seconddetection time point to the first detection time point; and

(iv) a change angle of the direction of the vehicle in the period fromthe second detection time point to the first detection time point.

When the calculated moving speed is equal to or less than apredetermined stationary object determination threshold (substantiallyclose to “0”), the CPU determines that the newly detected object is thestationary object. Next, the following cases will be described.

(Case 1): the new object is the stationary object (see FIG. 8 ).

(Case 2): the new object is the moving object (see FIGS. 9 to 13 ).

(Case 1): The New Object is the Stationary Object

When the CPU determines that the new object is the stationary object atStep 615, the CPU proceeds to Step 620 to determine whether or not atleast part of the stationary object is present within a “vehicletraveling area”. This condition as to whether the stationary object ispresent within the vehicle traveling area is referred to as a “firstcondition (or cancel condition)” for the sake of convenience.

The vehicle traveling area is an area through which the vehicle body isexpected to pass when the vehicle moves to the target region along thetarget path. In other words, the vehicle traveling area is an area whichis expected to be occupied by the vehicle body when the vehicle moves tothe target region along the target path. The CPU may set the vehicletraveling area on the assumption that the width in the right-leftdirection of the vehicle body is larger by a predetermined length(margin) than the actual width of the vehicle body and/or the length inthe longitudinal direction of the vehicle body is larger by thepredetermined length (margin) than the actual length of the vehiclebody. The first condition (cancel condition) is a condition which issatisfied when there is a high possibility that the “new object which isthe stationary object” is an obstacle for obstructing the movement ofthe vehicle along the target path.

In an example of FIG. 8 , a vehicle traveling area At is an areasurrounded (defined) by (i) a line LL, (ii) a line LR, (iii) a front endportion of the vehicle 100 when the vehicle 100 is at the currentposition Pnow, and (iv) a rear end portion of the vehicle 100 when thevehicle reaches the target position Ptgt1 (=the final target positionPtgt). When the stationary object (see a stationary object SO in FIG. 8) is present in the vehicle traveling region At, the stationary objectobstructs the traveling/movement of the vehicle 100 according to theperpendicular parking assist control (that is, the automatic steeringcontrol for moving the vehicle along the target path). It is consideredthat the stationary object does not move even after a while. Therefore,in this case, the CPU immediately cancels the perpendicular parkingassist control.

More specifically, when the stationary object is present within thevehicle traveling region (that is, the first condition is satisfied),the CPU makes a “Yes” determination at Step 620. Next, the CPUsequentially executes the following processes of Steps 625 and 630, andthen, proceeds to Step 695 to tentatively terminate the present routine.

Step 625: the CPU executes a cancel process for canceling theperpendicular parking assist control. Specifically, the CPU transmitsthe brake control signal to the brake ECU 30 to thereby stop the vehicle100. Further, the CPU displays on the screen a message that theperpendicular parking assist control is cancelled (see a message 1005illustrated in FIG. 14 described later). The CPU causes the speaker 86to speak the message displayed on the screen. In addition, the CPUremoves/erases the steering assist data from the RAM 10 b.

Step 630: the CPU sets the request flag FHS, the execution flag FHE andthe pause flag FHP to “0”, respectively.

As a result, the driver can immediately recognize that the perpendicularparking assist control is cancelled. The perpendicular parking assistcontrol is not restarted until the perpendicular parking mode is againselected through the predetermined operation of the steering assistswitch 85 (see Steps 310 and 320 in FIG. 3 , and Step 410 in FIG. 4 ).In other words, the CPU does not perform the automatic steering controluntil the target region is newly set after the time point at which thesteering assist control is cancelled, and until the target path and thesteering angle pattern, etc. are newly set/determined with respect tothe newly set target region.

At the time point at which the CPU executes the processing of Step 620,when the stationary object is not present within the vehicle travelingarea (the first condition is not satisfied), the CPU makes a “No”determination at Step 620, and proceeds directly to Step 695 totentatively terminate the present routine.

(Case 2): The New Object is the Moving Object

When the CPU determines that the new object is the moving object at Step615, the CPU makes a “No” determination at Step 615, and proceeds toStep 635. The CPU determines whether or not either one of the followingconditions E1 and E2 is satisfied. This condition including theconditions E1 and E2 is referred to as a “second condition (or pausecondition)” for the sake of convenience. The second condition (pausecondition) is a condition which is satisfied when there is a highpossibility that the “new object which is the moving object” is anobstacle for obstructing the movement of the vehicle along the targetpath.

(Condition E1): the new object (moving object) is present (moving)within the vehicle traveling area (see a moving object MO in FIG. 9 ).

(Condition E2): the new object (moving object) is moving toward thevehicle traveling area from the outside of the vehicle traveling area(see a moving object MO in FIG. 10 ). That is, the new object isapproaching the vehicle traveling area.

The CPU sets a half line extending along the moving direction of themoving object from the current position of the moving object on thetwo-dimensional map. When the half line passes through the vehicletraveling region At where the vehicle is expected to travel, the CPUdetermines that the moving object is moving toward the vehicle travelingarea At.

When the condition E1 is satisfied, as illustrated in FIG. 9 , there isa high possibility that the moving object MO obstructs thetraveling/movement of the vehicle 100 according to the perpendicularparking assist control (that is, the automatic steering control formoving the vehicle along the target path). However, when a certainperiod of time elapses, as shown in FIG. 11 , there is a possibilitythat the moving object MO moves to the outside of the vehicle travelingregion At and moves in a direction away from the vehicle travelingregion At. In the situation shown in FIG. 11 , the moving object MO doesnot obstruct the traveling/movement of the vehicle 100 according to theperpendicular parking assist control.

When the condition E2 is satisfied, as illustrated in FIG. 10 , there isa high possibility that the moving object MO obstructs thetraveling/movement of the vehicle 100 according to the perpendicularparking assist control. However, when a certain period of time elapses,as shown in FIG. 12 , there is a possibility that the moving object MOstops at a position outside the vehicle traveling area At beforeentering the vehicle traveling area At. In another case, as shown inFIG. 11 , there is a possibility that the moving object MO moves to theoutside of the vehicle traveling region At and moves in a direction awayfrom the vehicle traveling region At. In these situations, the movingobject MO does not obstruct the traveling/movement of the vehicle 100according to the perpendicular parking assist control.

That is, even if the second condition is satisfied, after a certainperiod of time elapses, there is possibility that the second conditionis not satisfied. Therefore, when the second condition is satisfied, theCPU pauses (temporarily stops) the perpendicular parking assist controlin place of immediately canceling that control. In this case, the CPUmaintains (holds) the steering assist data (including the final targetregion, the final target position, the final target path, the steeringangle pattern and the like) without removing/erasing that data from RAM10 b.

More specifically, when the second condition is satisfied, the CPU makesa “Yes” determination at Step 635. Next, the CPU sequentially executesthe following processes of Steps 640 and 645, and then, proceeds to Step695 to tentatively terminate the present routine.

Step 640: the CPU executes a pause process for pausing the perpendicularparking assist control. Specifically, the CPU transmits the brakecontrol signal to the brake ECU 30 to thereby stop the vehicle 100.Further, the CPU displays on the screen a message that the perpendicularparking assist control is paused (see a message 1101 illustrated in FIG.15 described later). The CPU causes the speaker 86 to speak the messagedisplayed on the screen. Therefore, the driver can immediately recognizethat the perpendicular parking assist control is paused. In addition,the CPU maintains (holds/keeps) the steering assist data on the RAM 10 bwithout erasing that data from the RAM 10 b.

Step 645: the CPU sets the request flag FHS to “1”, sets the executionflag FHE to “0”, and sets the pause flag FHP to “1”. In this manner, thepause flag FHP is set to “1” only when the perpendicular parking assistcontrol is paused.

Further, the CPU starts processing from Step 700 of FIG. 7 at apredetermined timing, and proceeds to Step 710 to determine whether ornot the value of the pause flag FHP is “1”. When the value of the pauseflag FHP is not “1”, the CPU makes a “No” determination at Step 710, andproceeds directly to Step 795 to tentatively terminate the presentroutine.

Meanwhile, when the value of the pause flag FHP is “1”, the CPU makes a“Yes” determination at Step 710, and proceeds to Step 720 to determinewhether or not either one of the following conditions F1 and F2 issatisfied. This condition including the conditions F1 and F2 is referredto as a “third condition (or resume condition)” for the sake ofconvenience. The third condition (resume condition) is a condition whichis satisfied when there is a high possibility that the “new object whichis the moving object” is not an obstacle for obstructing the movement ofthe vehicle along the target path.

(Condition F1): the new object (moving object) is present at a positionoutside of the vehicle traveling area, and is moving in a direction awayfrom the vehicle traveling area (see the moving object MO in FIG. 11 ).

(Condition F2): the new object (moving object) is present at a positionoutside of the vehicle traveling area, and is in a stopped state (seethe moving object MO in FIG. 12 ).

When the third condition is satisfied, the new object (moving object) nolonger be an obstacle which obstructs the movement of the vehicle 100according to the perpendicular parking assist control. In this case, theCPU makes a “Yes” determination at Step 720, and proceeds to Step 730 toexecute a resume process for resuming the perpendicular parking assistcontrol.

Specifically, as illustrated in FIG. 16 , the CPU displays on the screena resume button 1201 and a message 1202 that requests the driver to pusha brake pedal and push the resume button. Further, the CPU causes thespeaker 86 to speak the message 1202 displayed on the screen.

As the CPU proceeds to Step 740, the CPU determines whether or not thedriver pushes the resume button 1201 in a state in which the driverpushes the brake pedal. That is, the CPU determines whether or not apredetermined operation (resume operation) for resuming theperpendicular parking assist control is performed by the driver. Whenthe resume operation is not performed by the driver, the CPU makes a“No” determination at Step 740, and proceeds directly to Step 795 totentatively terminate the present routine. As a result, since the pauseflag FHP is maintained at “1”, the CPU repeatedly executes the processesof Steps 710 to 740.

When the resume operation is performed by the driver, the CPU makes a“Yes” determination at Step 740, and proceeds to Step 750. At Step 750,the CPU sets the request flag FHS to “1”, sets the execution flag FHE to“1”, and sets the pause flag FHP to “0”. In this case, the CPU stopstransmitting the brake control signal to the brake ECU 30. Further, theCPU may display on the screen a message that the perpendicular parkingassist control is resumed, and cause the speaker 86 to speak the messagedisplayed on the screen.

As a result, in the routine of FIG. 3 , the CPU makes a “No”determination at Step 310, and proceeds directly to Step 395. Further,in the routine of FIG. 4 , the CPU makes a “Yes” determination at Step410, and proceeds to Step 420 and the following steps. When the currentposition of the shift lever is the position displayed on the screen, atStep 440, the CPU resumes the automatic steering control in accordancewith the steering assist data (the steering angle pattern, and the like)which has been maintained/held in the RAM 10 b.

On the other hand, when the third condition is not satisfied at the timepoint at which the CPU executes the processing of Step 720 in theroutine of FIG. 7 , the CPU makes a “No” determination at Step 720, andproceeds to Step 760. At Step 760, the CPU determines whether or not anelapsed time from the time point at which the pause flag FHP is changedfrom “0” to “1” is equal to or larger than a predetermined timethreshold (first time threshold) Th1. This elapsed time is an elapsedtime from at the time point at which the pause of the perpendicularparking assist control is started, and is also referred to as a “pauseduration time”. When the pause duration time is less than the timethreshold Th1, the CPU makes a “No” determination at Step 760, andproceeds directly to Step 795 to tentatively terminate the presentroutine. Therefore, the pause of the steering assist control iscontinued.

For example, as illustrated in FIG. 13 , it is assumed that the movingobject MO enters the vehicle traveling area At, and then, the movingobject MO stops at a position within the vehicle traveling area At overthe time threshold Th1 or more. When the pause duration time becomesequal to or larger than the time threshold Th1, the CPU makes a “Yes”determination at Step 760. Next, the CPU sequentially executes thefollowing processes of Steps 770 and 780, and then, proceeds to Step 795to tentatively terminate the present routine.

Step 770: The CPU executes the cancel process for canceling theperpendicular parking assist control in the same way as the process ofStep 625. Therefore, the CPU removes/erases the steering assist datafrom the RAM 10 b.

Step 780: The CPU sets the request flag FHS, the execution flag FHE, andthe pause flag FHP to “0”, respectively, in the same way as the processof Step 630.

As described above, the steering assist control is cancelled at the timepoint at which the time threshold Th1 elapses from the time point atwhich the pause of the steering assist control is started. In this case,the CPU does not perform the automatic steering control (steering assistcontrol) until the target region is newly set after the time point atwhich the steering assist control is cancelled, and until the steeringassist data is newly set/determined with respect to the newly set targetregion.

Next, with reference to FIGS. 14 to 16 , contents displayed on the touchpanel 73 when the display mode of the image displayed on the touch panel73 is the steering assist mode will be described. When the display modeis the steering assist mode, on the touch panel 73, an overhead viewimage (bird's-eye view image) 1001, a traveling direction image 1002, atravel direction message 1003 indicating a direction in which thevehicle is to be moved, and a vehicle mark 1004 are displayed.

The overhead view image 1001 is an image including an own vehicle 1001 aand a peripheral region 1001 b of the own vehicle 1001 a. The peripheralregion 1001 b includes a target region 1001 c corresponding to thetarget position, partition lines and objects present in the periphery ofthe own vehicle 1001 a. The traveling direction image 1002 is an imageof the camera corresponding to the travel direction of the vehicle. Whenthe vehicle moves forward, the traveling direction image 1002 is animage of the camera 84 a. When the vehicle moves backward, the travelingdirection image 1002 is an image of the camera 84 b.

The travel direction message 1003 is a message including information(that is, the position of the shift lever) on the direction in which theown vehicle is to be moved for performing the perpendicular parkingassist control. The vehicle mark 1004 is a mark indicating whether thearea displayed on the travel direction image 1002 is an area on thefront side of the vehicle or the rear side of the vehicle.

As illustrated in FIG. 14 , when the steering assist control iscancelled, the CPU displays a message 1005 that the perpendicularparking assist control is cancelled so as to overlap with the overheadview image 1001.

As illustrated in FIG. 15 , when the steering assist control is paused,the CPU displays a message 1101 that the perpendicular parking assistcontrol is paused so as to overlap with the overhead view image 1001. Inthis case, the CPU may display a mark 1102 so as to overlap with thetravel direction image 1002. The mark 1102 is a mark indicating that thenew object (moving object) is approaching the own vehicle from whichside of the right side and the left side with respect to the ownvehicle.

As illustrated in FIG. 16 , when the above-mentioned third condition(resume condition) is satisfied after the steering assist control ispaused, the CPU displays a resume button 1201 and a message 1202 so asto overlap with the overhead view image 1001.

As described above, when a new object is detected in a “period from thetime point of the start of the automatic steering control until theposition of the vehicle reaches the target position”, the firstapparatus determines whether the new object is the stationary object orthe moving object. Further, the first apparatus cancels or pauses thesteering assist control depending on whether the new object is thestationary object or the moving object, and informs the driver that thesteering assist control is cancelled or paused. It is assumed that thedetected new object is the stationary object, and there is a highpossibility that the stationary object is an obstacle which obstructsthe vehicle when the vehicle travels along the target path. In thissituation, the first apparatus cancels the steering assist control andinforms the driver that the steering assist control is cancelled.Therefore, the driver can immediately recognize/notice that the vehiclecannot be parked unless the vehicle is moved from the current positionto another position. The driver can immediately search for anotherregion in which the vehicle can be parked. As a result, the timerequired for parking the vehicle is shortened as compared to the firstrelated-art apparatus.

It is assumed that the detected new object is the moving object, andthere is a high possibility that the moving object is an obstacle whichobstructs the vehicle when the vehicle travels along the target path. Inthis situation, the first apparatus pauses the steering assist controland informs the driver that the steering assist control is paused.Therefore, the driver can understand that it is not necessary to movethe vehicle from the current position to another position, and it onlyhas to wait for a while. When the predetermined resume condition issatisfied while the driver is waiting, the first apparatus resumes thesteering assist control in accordance with the target path used untilthe time point at which the pause of the steering assist control isstarted (that is, the target path which has been maintained/held fromthe time point at which the steering assist control is paused).

Further, the first apparatus sets the vehicle traveling area At which isan area through which the vehicle body is expected to pass when thevehicle travels along the target path. The first apparatus determineswhether or not the first condition (cancel condition) is satisfied basedon the positional relationship between the vehicle traveling area At andthe stationary object. It is assumed that, although the stationaryobject is present within the vehicle traveling area At, the stationaryobject is away from the vehicle. In this situation, the secondrelated-art apparatus cancels the steering assist control when thedistance between the vehicle and the stationary object is equal to orless than the predetermined distance. Therefore, the time until thesteering assist control is cancelled becomes longer. Meanwhile, thefirst apparatus immediately cancels the steering assist control in theabove-mentioned situation. The driver can immediately search for anotherregion in which the vehicle can be parked. As a result, the timerequired for parking the vehicle is shortened as compared to the secondrelated-art apparatus.

Further, the first apparatus determines whether or not the secondcondition (pause condition) is satisfied based on the positionalrelationship between the vehicle traveling area At and the movingobject, and the moving direction of the moving object. It is assumedthat, although the moving object is present within the vehicle travelingarea At, the moving object is away from the vehicle. In this situation,the first related-art apparatus pauses the steering assist control whenthe distance between the vehicle and the moving object is equal to orless than the predetermined distance. Therefore, the vehicle may get tooclose to the moving object. Meanwhile, the first apparatus immediatelypauses the steering assist control in the above-mentioned situation. Itis possible to prevent the vehicle from getting too close to the movingobject.

Further, the first apparatus determines whether or not the thirdcondition (resume condition) is satisfied based on the positionalrelationship between the vehicle traveling area At and the movingobject, and the moving direction of the moving object. It is assumedthat, although the moving object moves outside of the vehicle travelingarea At after the steering assist control is paused, the distancebetween the vehicle and the moving object is still equal to or less thanthe predetermined distance. In this situation, the first related-artapparatus cannot resume the steering assist control as long as thedistance between the vehicle and the moving object is equal to or lessthan the predetermined distance. Meanwhile, because the moving object ispresent at a position outside of the vehicle traveling area At and themoving object is moving in a direction away from the vehicle travelingarea At, the first apparatus determines that the third condition (resumecondition) is satisfied, and therefore, resumes the steering assistcontrol. As a result, a time required for resuming the steering assistcontrol is shortened as compared to the first related-art apparatus.

Further, at the time point at which the time threshold Th1 elapses fromthe time point at which the pause of the steering assist control isstarted, the first apparatus cancels the steering assist control, andinforms the driver that the steering assist control is cancelled. It isassumed that the detected new object is the moving object, and themoving object gets close to the target path and is in a stopped statenear the target path. In this situation, the first related-art apparatusrecalculates the target path. However, there is also a high possibilitythat the first related-art apparatus cannot calculate another targetpath which allows the vehicle to move to the target region withoutcontacting the obstacle (moving object). Therefore, it is oftennecessary to move the vehicle from the current position to anotherposition. Further, in the first related-art apparatus, the driver has towait for the result of the recalculation of the target path. For thisreason, the time required for parking the vehicle becomes longer. On theother hand, at the time point at which the time threshold Th1 elapsesfrom the time point at which the steering assist control is paused, thefirst apparatus immediately cancels the steering assist control. Thedriver can immediately search for another region in which the vehiclecan be parked. As a result, the time required for parking the vehicle isshortened as compared to the first related-art apparatus.

Second Embodiment

Next, a steering assist apparatus (hereinafter also referred to as a“second apparatus”) according to a second embodiment will be described.The second apparatus is different from the first apparatus in that, whena new object is detected on and after at the path setting time point atwhich the final steering assist data is set/determined, even before theautomatic steering control is started, the second apparatus cancels orpauses the perpendicular parking assist control in accordance with thestate of the detected new object. More specifically, the secondapparatus is different from the first apparatus only in that the CPU ofthe second apparatus executes a routine of FIG. 17 shown by a flowchartin place of the flowchart of FIG. 6 . A description is now mainly givenof this difference.

The routine shown in FIG. 17 is a routine in which Step 610 of theroutine in FIG. 6 is replaced with Step 1710. In FIG. 17 , for each stepfor executing the same process as the step shown in FIG. 6 , the samereference numeral in FIG. 6 is appended. Therefore, detaileddescriptions of Steps in FIG. 17 denoted by the same reference numeralsas in FIG. 6 will be omitted.

The CPU starts processing from Step 1700 of FIG. 17 at a predeterminedtiming, and proceeds to Step 605. When all of the above-mentionedconditions D1 to D3 are satisfied, the CPU makes a “Yes” determinationat Step 605, and proceeds to Step 1710.

At Step 1710, the CPU determines whether or not a new object has beendetected after the execution flag FHE is changed to “1” (that is, in aperiod from the path setting time point until the time point at whichthe position of the vehicle reaches the target position). When a newobject has not been detected, the CPU makes a “No” determination at Step1710, and proceeds directly to Step 1795 to tentatively terminate thepresent routine.

On the other hand, when a new object has been detected after theexecution flag FHE is changed to “1”, the CPU makes a “Yes”determination at Step 1710, and executes the processes of Steps 615 to645 as described above. Then, the CPU proceeds to Step 1795 totentatively terminate the present routine.

It is assumed that, at the time point at which the CPU proceeds to Step1710, the CPU proceeds to Step 430 in the routine of FIG. 4 . At thistime point, the direction in which the vehicle is to be moved(specifically, the position of the shift lever) is displayed on thescreen. However, the driver has not yet moved the position of the shiftlever to the position displayed on the screen. In this situation, theCPU makes a “No” determination at Step 430, and tentatively terminatesthe present routine of FIG. 4 . Therefore, the perpendicular parkingassist control is not started. However, a situation may occur in which anew object (moving object) gets close to the vehicle on and after thepath setting time point, and before the perpendicular parking assistcontrol is started. Even in this situation, the CPU makes a “Yes”determination at Step 1710. The CPU executes the processes of Steps 615to 645 as described above to thereby execute the cancel process or thepause process.

The present disclosure is not limited to the above-mentionedembodiments, and various changes can be adopted within the scope of thepresent disclosure.

When the vehicle can move to the tentative target position through onlyone backward movement, the CPU may calculate, as the tentative targetpath, a path including a switching of the travel direction of thevehicle. Such a path may be (i) a path for moving the vehicle forwardand then moving the vehicle backward, or (ii) a path for moving thevehicle backward, moving the vehicle forward, and then moving thevehicle backward. For example, as illustrated in FIG. 18 , the steeringassist ECU 10 calculates a first path LtgtA for moving the vehicleforward from the current position Pnow to a travel-direction-switchingposition Psw, and a second path LtgtB for moving the vehicle backwardfrom the travel-direction-switching position Psw to the target positionPtgt. The travel-direction-switching position Psw is a position at whichthe vehicle temporarily stops in order to switch the position of theshift lever from the drive position (D) to the reverse position (R).Hereinafter, the travel-direction-switching position is simply referredto as a “switching position”. The steering assist ECU 10 sets/determinesthe first path LtgtA and the second path LtgtB as the tentative targetpath.

In the above situation, the CPU sets a first vehicle traveling area At1and a second vehicle traveling area At2. The first vehicle travelingarea At1 is an area through which the vehicle body is expected to passwhen the vehicle moves from the current position Pnow to the switchingposition Psw along the first path LtgtA. In other words, the firstvehicle traveling area At1 is an area which is expected to be occupiedby the vehicle body when the vehicle moves from the current positionPnow to the switching position Psw along the first path LtgtA. The firstvehicle traveling area At1 is an area surrounded (defined) by (i) a lineLL1, (ii) a line LR1, (iii) the front end portion of the vehicle 100when the vehicle 100 is at the current position Pnow, and (iv) the frontend portion of the vehicle 100 when the vehicle reaches the switchingposition Psw. The second vehicle traveling area At2 is an area throughwhich the vehicle body is expected to pass when the vehicle moves fromthe switching position Psw to the target position Ptgt along the secondpath LtgtB. In other words, the second vehicle traveling area At2 is anarea which is expected to be occupied by the vehicle body when thevehicle moves from the switching position Psw to the target positionPtgt along the second path LtgtB. The second vehicle traveling area At2is an area surrounded (defined) by (i) a line LL2, (ii) a line LR2,(iii) the front end portion of the vehicle 100 when the vehicle 100 isat the switching position Psw, and (iv) the rear end portion of thevehicle 100 when the vehicle reaches the target position Ptgt.

In a case where the vehicle 100 moves along the first path LtgtA, whenthe CPU proceeds to Step 635 in the routine of FIG. 6 , the CPU maydetermine whether or not the second condition (pause condition) issatisfied by using only the first vehicle traveling area At1. That is,when either one of the following conditions E1a and E2a is satisfied,the CPU determines that the second condition is satisfied.

(Condition E1a): the new object (moving object) is present (moving)within the first vehicle traveling area At1.

(Condition E2a): the new object (moving object) is moving toward thefirst vehicle traveling area At1 from the outside of the first vehicletraveling area At1.

As illustrated in FIG. 18 , it is assumed that, when the vehicle 100moves along the first path LtgtA, the CPU has newly detected a firstobject (moving object) OB1 in the periphery of the vehicle 100. In thissituation, the first object OB1 obstructs the traveling of the vehicle100 while the vehicle 100 moves to the switching position Psw. Since thesecond condition is satisfied, the CPU makes a “Yes” determination atStep 635, and then, executes the subsequent process (that is, the pauseprocess).

On the other hand, it is assumed that, when the vehicle 100 moves alongthe first path LtgtA, the CPU has newly detected a second object (movingobject) OB2 in the periphery of the vehicle 100. Although the secondobject OB1 is present within the second vehicle traveling area At2, thesecond object OB1 is moving at a position outside of the first vehicletraveling area At1 and moving in a direction away from the first vehicletraveling area At1. In this situation, the second object OB2 does notobstruct the traveling of the vehicle 100 while the vehicle 100 moves tothe switching position Psw. In such a situation, according to thismodified example, the CPU determines that the second condition is notsatisfied. Therefore, the CPU continues performing the perpendicularparking assist control. The perpendicular parking assist control is notpaused unnecessarily, and therefore, it is possible to reduce anopportunity for the driver to feel inconvenience.

Further, in a case where the vehicle 100 moves along the second pathLtgtB, when the CPU proceeds to Step 635 in the routine of FIG. 6 , theCPU may determine whether or not the second condition (pause condition)is satisfied by using only the second vehicle traveling area At2. Thatis, when either one of the following conditions E1b and E2b issatisfied, the CPU determines that the second condition is satisfied.

(Condition E1 b): the new object (moving object) is present (moving)within the second vehicle traveling area At2.

(Condition E2b): the new object (moving object) is moving toward thesecond vehicle traveling area At2 from the outside of the second vehicletraveling area At2.

The steering assist control according to the parallel parking mode andthe steering assist control according to the exit-from-parking-spacemode are controls similar to the perpendicular parking assist control,except that target regions to which the own vehicle is to be finallymoved are different from each other. Therefore, the routines describedabove (the routine of FIG. 6 , the routine of FIG. 7 , and the routineof FIG. 17 ) can be applied to the steering assist control based on theparallel parking mode, and the steering assist control based on theexit-from-parking-space mode.

The cancel condition (first condition) may be a condition which issatisfied when a distance in the travel direction of the vehicle betweenthe vehicle and the new object (stationary object) is equal to or lessthan a predetermined distance.

Regarding the pause condition (second condition), the condition E2 mayfurther include the following condition: a required time Tc until themoving object reaches the vehicle traveling region At is equal to orless than a predetermined second time threshold Th2. According to thisconfiguration, when the time until the moving object reaches the vehicletraveling region At is long, the vehicle can be moved to an positionnear the target position Fp without pausing the steering assist controluntil the moving object approaches the vehicle traveling region At.After that, the steering assist control can be paused.

The pause condition (second condition) may be a condition which issatisfied when the distance between the new object (moving object) andthe vehicle is equal to or less than a predetermined distance and themoving object is approaching the vehicle.

The steering assist ECU 10 may automatically perform a shift control byusing the SBW ECU 60, a driving force control by using the engine ECU20, and a braking force control by using the brake ECU 30 in addition tothe steering assist control. For example, the steering assist ECU 10 maytransmit a shift control signal to the SBW ECU 60 when the vehiclereaches the switching position, to thereby cause the SBW ECU 60 toperform the shift control. Further, the steering assist ECU 10 maycalculate a speed pattern for causing the vehicle to travel along thetarget path. The speed pattern is data that associates the position ofthe own vehicle on the target path and a travel speed with each other,and represents a change in the travel speed when the vehicle travelsalong the target path. The steering assist ECU 10 may transmit a brakingforce control signal to the brake ECU 30 in accordance with the speedpattern, to thereby cause the brake ECU 30 to perform the braking forcecontrol. Further, the steering assist ECU 10 may transmit a drivingforce control signal to the engine ECU 20 in accordance with the speedpattern, to thereby cause the engine ECU 20 to perform the driving forcecontrol.

The steering assist switch 85 is only required to be a switch to beoperated when the driver requests the steering assist to generate asignal indicating the request (that is, when the steering assist requestfor parking the vehicle or exiting the vehicle from the parking space ismade). Further, the steering assist switch may be an apparatusconfigured to use a speech recognition apparatus to recognize an oral(voice) request from the driver for the steering assist. This speechrecognition apparatus is equivalent to a switch to be operated throughspeech (oral sound), and can serve as the operation switch (operationunit) in the above embodiments. In this configuration, the steeringassist ECU has a request monitoring function for determining whether ornot the steering assist request for parking the vehicle or exiting thevehicle from the parking space is made through the switch operation bythe driver and/or the voice of the driver.

The guidance for parking the vehicle or exiting the vehicle from theparking space may be displayed on the display device 51 in place of orin addition to the touch panel 73. The meter ECU 50 may on the displaydevice 51 display the guidance for parking the vehicle or exiting thevehicle from the parking space in accordance with a display commandtransmitted from the steering assist ECU 10. In addition, the displaydevice 51 may include a display dedicated to the guidance for parkingthe vehicle or exiting the vehicle from the parking space.

The predetermined operation (resume operation) for resuming theperpendicular parking assist control is not limited to the aboveexample. The resume operation may be a simple operation. For example,the resume operation may be only an operation that the driver steps onthe brake pedal. Furthermore, in a configuration in which theperpendicular parking assist control further includes the driving forcecontrol using by the engine ECU 20 and the braking force control byusing the brake ECU 30, the above resume operation may be omitted. Inthis configuration, at the time point at which the resume condition issatisfied, the perpendicular parking assist control is resumed withoutthe resume operation by the driver.

The steering assist ECU 10 may be further configured to perform aforward-moving perpendicular parking assist control for performing thesteering assist when the own vehicle is moved forward and parked in sucha manner that the longitudinal direction of the own vehicle and thelongitudinal direction of another vehicle are parallel to each other. Inthis configuration, every time the steering assist switch 85 isdepressed, the steering assist ECU 10 switches the switch mode to thebackward-moving perpendicular parking mode, the forward-movingperpendicular parking mode, the parallel parking mode, theexit-from-parking-space mode, and the non-setting mode in this order.

In place of the steering assist control for automatically changing thesteering angle of steered wheels, the steering assist ECU 10 mayinstruct the driver about the steering direction of the steering wheelas the steering assist. Specifically, the steering assist ECU 10 maycause the speaker 86 to generate sound and cause the display device 51to display a message in such a manner that the own vehicle moves alongthe target path.

What is claimed is:
 1. A parking assist apparatus for a vehicle, comprising: an information acquiring device configured to acquire information on an object present in a periphery of the vehicle; and an electronic control unit including at least one processor programmed to: set a target region, and set, as a target path, a path for moving the vehicle to the target region, the target region being a region which is occupied by the vehicle at a time point at which the vehicle completes parking or exiting from a parking space on an assumption that the vehicle moves from a current position of the vehicle; and perform a parking assist control for changing a steering angle of the vehicle according to the set target path in such a manner that the vehicle moves along the target path, wherein, in a case where the information acquiring device acquires, in a period from a first time point on and after a path setting time point at which the target path is set until a second time point at which the vehicle reaches the target region, information on a new object which has not been detected at the path setting time point, pause the parking assist control, when a pause condition is satisfied, the pause condition being a condition which is satisfied when the new object is on the target path, and wherein, in a pause period from a fourth time point at which the pause of the parking assist control is started until a predetermined time threshold elapses, when a resume condition is satisfied, resume the parking assist control in accordance with the target path used until the fourth time point at which the pause of the parking assist control is started, the resume condition being a condition which is satisfied when there is a high possibility that the new object is not an obstacle which obstructs the vehicle when the vehicle travels along the target path used until the fourth time point at which the pause of the parking assist control is started.
 2. The parking assist apparatus according to claim 1, wherein, when the resume condition is satisfied in the pause period, the ECU is programmed to cancel the parking assist control at a time point at which the pause period elapses, and inform the driver that the parking assist control is cancelled, after at a time point at which the parking assist control is cancelled, the ECU is programed to not perform the parking assist control until the path setting module sets newly the target path and sets the target path with respect to the newly set target region.
 3. The parking assist apparatus according to claim 1, wherein, when either one of a first resume condition and a second resume condition is satisfied in the pause period, the ECU is programmed to determine that the resume condition is satisfied, the first resume condition being a condition which is satisfied when the new object is moving in a direction away from the vehicle traveling area at a position outside of the vehicle traveling area, and the second resume condition being a condition which is satisfied when the new object is in a stopped state at a position outside of the vehicle traveling area.
 4. The parking assist apparatus according to claim 1, wherein, when the pause condition is satisfied, the ECU is programmed to inform the driver that the parking assist control is paused.
 5. A parking assist apparatus for a vehicle, comprising: an information acquiring device configured to acquire information on an object present in a periphery of the vehicle; and an electronic control unit including at least one processor programmed to: set a target region, and set, as a target path, a path for moving the vehicle to the target region, the target region being a region which is occupied by the vehicle at a time point at which the vehicle completes parking or exiting from a parking space on an assumption that the vehicle moves from a current position of the vehicle; and perform a parking assist control for changing a steering angle of the vehicle according to the set target path in such a manner that the vehicle moves along the target path, wherein, in a case where the information acquiring device acquires, in a period from a first time point on and after a path setting time point at which the target path is set until a second time point at which the vehicle reaches the target region, information on a new object which has not been detected at the path setting time point, and wherein the new object is a moving object, pause the parking assist control when a pause condition is satisfied, the pause condition being a condition which is satisfied when the new object is on the target path, and wherein, when either one of a first pause condition and a second pause condition is satisfied, the ECU is programmed to determine that the pause condition is satisfied, the first pause condition being a condition which is satisfied when the new object is moving within a vehicle traveling area, and the second pause condition being a condition which is satisfied when the new object is moving toward the vehicle traveling area from an outside of the vehicle traveling area, the vehicle traveling area including an area through which a vehicle body of the vehicle is expected to pass when the vehicle travels along the target path.
 6. The parking assist apparatus according to claim 5, wherein the ECU is programmed to, when the vehicle cannot move to the target region through one backward movement or one forward movement, set a first path and a second path as the target path, the first path being a path for moving the vehicle from the current position to a travel-direction-switching position for switching a travel direction of the vehicle, and the second path being a path for moving the vehicle from the travel-direction- switching position to the target region, and set a first vehicle traveling area and a second vehicle traveling area, the first vehicle traveling area including an area through which the vehicle body is expected to pass when the vehicle travels along the first path, and the second vehicle traveling area including an area through which the vehicle body is expected to pass when the vehicle travels along the second path, and wherein, in the case that the new object is the moving object, while the vehicle travels along the first path, when either one of a third pause condition and a fourth pause condition is satisfied, determine that the pause condition is satisfied, the third pause condition being a condition which is satisfied when the new object is moving within the first vehicle traveling area, and the fourth pause condition being a condition which is satisfied when the new object is moving toward the first vehicle traveling area from an outside of the first vehicle traveling area, and while the vehicle travels along the second path, when either one of a fifth pause condition and a sixth pause condition is satisfied, determine that the pause condition is satisfied, the fifth pause condition being a condition which is satisfied when the new object is moving within the second vehicle traveling area, and the sixth pause condition being a condition which is satisfied when the new object is moving toward the second vehicle traveling area from an outside of the second vehicle traveling area. 